From 8afeaafcb06c07058e1f296e3d3867048c01d18c Mon Sep 17 00:00:00 2001 From: Isaac Muse Date: Mon, 23 Jan 2017 12:31:41 -0700 Subject: Create additional references for duplicate footnotes (#534) Track when we find duplicate footnote references and create unique ids for them. Then add an additional tree-processor after inline to go back and update the footnotes with additional back references that link to the duplicate footnote references. Fixes #468. --- markdown/extensions/footnotes.py | 98 ++++++++++++++++++++++++++++++++++-- tests/extensions/extra/footnote.html | 12 +++++ tests/extensions/extra/footnote.txt | 10 ++++ 3 files changed, 115 insertions(+), 5 deletions(-) diff --git a/markdown/extensions/footnotes.py b/markdown/extensions/footnotes.py index b52815f..368334d 100644 --- a/markdown/extensions/footnotes.py +++ b/markdown/extensions/footnotes.py @@ -23,11 +23,13 @@ from ..postprocessors import Postprocessor from ..util import etree, text_type from ..odict import OrderedDict import re +import copy FN_BACKLINK_TEXT = "zz1337820767766393qq" NBSP_PLACEHOLDER = "qq3936677670287331zz" DEF_RE = re.compile(r'[ ]{0,3}\[\^([^\]]*)\]:\s*(.*)') TABBED_RE = re.compile(r'((\t)|( ))(.*)') +RE_REF_ID = re.compile(r'(fnref)(\d+)') class FootnoteExtension(Extension): @@ -53,6 +55,8 @@ class FootnoteExtension(Extension): # In multiple invocations, emit links that don't get tangled. self.unique_prefix = 0 + self.found_refs = {} + self.used_refs = set() self.reset() @@ -76,6 +80,15 @@ class FootnoteExtension(Extension): md.treeprocessors.add( "footnote", FootnoteTreeprocessor(self), "_begin" ) + + # Insert a tree-processor that will run after inline is done. + # In this tree-processor we want to check our duplicate footnote tracker + # And add additional backrefs to the footnote pointing back to the + # duplicated references. + md.treeprocessors.add( + "footnote-duplicate", FootnotePostTreeprocessor(self), '>inline' + ) + # Insert a postprocessor after amp_substitute oricessor md.postprocessors.add( "footnote", FootnotePostprocessor(self), ">amp_substitute" @@ -85,6 +98,29 @@ class FootnoteExtension(Extension): """ Clear footnotes on reset, and prepare for distinct document. """ self.footnotes = OrderedDict() self.unique_prefix += 1 + self.found_refs = {} + self.used_refs = set() + + def unique_ref(self, reference, found=False): + """ Get a unique reference if there are duplicates. """ + if not found: + return reference + + original_ref = reference + while reference in self.used_refs: + ref, rest = reference.split(self.get_separator(), 1) + m = RE_REF_ID.match(ref) + if m: + reference = '%s%d%s%s' % (m.group(1), int(m.group(2))+1, self.get_separator(), rest) + else: + reference = '%s%d%s%s' % (ref, 2, self.get_separator(), rest) + + self.used_refs.add(reference) + if original_ref in self.found_refs: + self.found_refs[original_ref] += 1 + else: + self.found_refs[original_ref] = 1 + return reference def findFootnotesPlaceholder(self, root): """ Return ElementTree Element that contains Footnote placeholder. """ @@ -120,13 +156,12 @@ class FootnoteExtension(Extension): else: return 'fn%s%s' % (self.get_separator(), id) - def makeFootnoteRefId(self, id): + def makeFootnoteRefId(self, id, found=False): """ Return footnote back-link id. """ if self.getConfig("UNIQUE_IDS"): - return 'fnref%s%d-%s' % (self.get_separator(), - self.unique_prefix, id) + return self.unique_ref('fnref%s%d-%s' % (self.get_separator(), self.unique_prefix, id), found) else: - return 'fnref%s%s' % (self.get_separator(), id) + return self.unique_ref('fnref%s%s' % (self.get_separator(), id), found) def makeFootnotesDiv(self, root): """ Return div of footnotes as et Element. """ @@ -270,7 +305,7 @@ class FootnotePattern(Pattern): if id in self.footnotes.footnotes.keys(): sup = etree.Element("sup") a = etree.SubElement(sup, "a") - sup.set('id', self.footnotes.makeFootnoteRefId(id)) + sup.set('id', self.footnotes.makeFootnoteRefId(id, found=True)) a.set('href', '#' + self.footnotes.makeFootnoteId(id)) if self.footnotes.md.output_format not in ['html5', 'xhtml5']: a.set('rel', 'footnote') # invalid in HTML5 @@ -281,6 +316,59 @@ class FootnotePattern(Pattern): return None +class FootnotePostTreeprocessor(Treeprocessor): + """ Ammend footnote div with duplicates. """ + + def __init__(self, footnotes): + self.footnotes = footnotes + + def add_duplicates(self, li, duplicates): + """ Adjust current li and add the duplicates: fnref2, fnref3, etc. """ + for link in li.iter('a'): + # Find the link that needs to be duplicated. + if link.attrib.get('class', '') == 'footnote-backref': + ref, rest = link.attrib['href'].split(self.footnotes.get_separator(), 1) + # Duplicate link the number of times we need to + # and point the to the appropriate references. + links = [] + for index in range(2, duplicates + 1): + sib_link = copy.deepcopy(link) + sib_link.attrib['href'] = '%s%d%s%s' % (ref, index, self.footnotes.get_separator(), rest) + links.append(sib_link) + self.offset += 1 + # Add all the new duplicate links. + el = list(li)[-1] + for l in links: + el.append(l) + break + + def get_num_duplicates(self, li): + """ Get the number of duplicate refs of the footnote. """ + fn, rest = li.attrib.get('id', '').split(self.footnotes.get_separator(), 1) + link_id = '%sref%s%s' % (fn, self.footnotes.get_separator(), rest) + return self.footnotes.found_refs.get(link_id, 0) + + def handle_duplicates(self, parent): + """ Find duplicate footnotes and format and add the duplicates. """ + for li in list(parent): + # Check number of duplicates footnotes and insert + # additional links if needed. + count = self.get_num_duplicates(li) + if count > 1: + self.add_duplicates(li, count) + + def run(self, root): + """ Crawl the footnote div and add missing duplicate footnotes. """ + self.offset = 0 + for div in root.iter('div'): + if div.attrib.get('class', '') == 'footnote': + # Footnotes shoul be under the first orderd list under + # the footnote div. So once we find it, quit. + for ol in div.iter('ol'): + self.handle_duplicates(ol) + break + + class FootnoteTreeprocessor(Treeprocessor): """ Build and append footnote div to end of document. """ diff --git a/tests/extensions/extra/footnote.html b/tests/extensions/extra/footnote.html index e5b41a7..9cf42ed 100644 --- a/tests/extensions/extra/footnote.html +++ b/tests/extensions/extra/footnote.html @@ -1,5 +1,8 @@

This is the body with a footnote1 or two2 or more3 4 5.

Also a reference that does not exist[^6].

+

Duplicate6 footnotes6 test6.

+

Duplicate7 footnotes7 test7.

+

Single after duplicates8.

    @@ -29,5 +32,14 @@ Second line of first paragraph is not intended. Nor is third... ↩

    +
  1. +

    1 ↩↩↩

    +
    2. +
  2. +

    2 ↩↩↩

    +
    3. +
  3. +

    3 ↩

    +
\ No newline at end of file diff --git a/tests/extensions/extra/footnote.txt b/tests/extensions/extra/footnote.txt index c5c1c92..f95ff2c 100644 --- a/tests/extensions/extra/footnote.txt +++ b/tests/extensions/extra/footnote.txt @@ -2,6 +2,12 @@ This is the body with a footnote[^1] or two[^2] or more[^3] [^4] [^5]. Also a reference that does not exist[^6]. +Duplicate[^a] footnotes[^a] test[^a]. + +Duplicate[^b] footnotes[^b] test[^b]. + +Single after duplicates[^c]. + [^1]: Footnote that ends with a list: * item 1 @@ -18,3 +24,7 @@ Also a reference that does not exist[^6]. [^5]: First line of first paragraph. Second line of first paragraph is not intended. Nor is third... + +[^a]: 1 +[^b]: 2 +[^c]: 3 -- cgit v1.2.3